Liquefied natural gas (LNG) is drawing attention as a clean energy source. LNG is produced by removing impurities such as carbon dioxide (CO2) and a sulfur component (for example, H2S) contained in natural gas, removing water therein, and liquefying the resultant natural gas by a liquefaction apparatus in an LNG plant.
In this process, a large amount of fuel exhaust gas including carbon dioxide is generated from a power source (for example, a boiler) that drives a carbon dioxide removing apparatus for removing the carbon dioxide in the natural gas, a liquefaction apparatus, or the like in a production process. The burnt fuel exhaust gas is discharged into the air without performing any processing. This fuel exhaust gas raises an environmental issue such as global warming.
Therefore, conventionally, there is proposed a method for press-fitting the CO2 together with water into an underground aquifer instead of discharging the CO2 into the air (Patent Document 1).
Patent Document 1: Japanese Patent Application-Laid-Open No. H6-170215